For the silylation of hydroxyl groups, it is known in the art to silylate a hydroxyl group-containing compound with a hydrosilane compound as a silylating agent in the presence of a transition metal-carrying catalyst. The catalyst is generally in the form of active carbon or a similar carrier having metallic palladium, metallic rhodium or metallic ruthenium supported thereon. The method using such transition metal-carrying catalysts has several problems. First, the catalysts themselves are expensive. The post treatment of the transition metal-carrying catalysts is dangerous since hydrogen is occluded in the catalysts at the end of reaction. The catalysts are difficult to handle since they are heterogeneous catalysts using carriers. The method is thus disadvantageous for industrial synthesis. See Bull. Chem. Soc. Jpn., 1989, 62, 2111; and Advances in Organometallic Chemistry, Vol. 19, 1981, pp. 213-255, Academic Press. It is also known to use homogeneous catalysts in the form of various transition metal complexes such as rhodium, iridium and cobalt complexes. The method using these transition metal complexes also has the problem that the catalysts themselves are expensive. In addition, for reaction of a silylating agent having a sterically bulky substituent, these catalysts are low catalytic and must be used in large amounts. These catalysts are thus rather unacceptable on practical use. See J. Organomet. Chem., 1976, 114, 135; J. Organomet. Chem., 1980, 192, 329; and Tetrahedron Lett., 1992, 33, 5044.